1. Technical Field
The present invention relates to an information processing device and particularly to an information processing device capable of selecting an appropriate communication rate used to exchange data with a data record medium.
2. Related Art
An example of a data record medium on which an information processing device such as a personal computer records data includes a CF (Compact Flash (registered trademark)) card. The information processing device compatible with this CF card is provided with a card slot for the CF card. When a user inserts the CF card into the card slot, the information processing device is able to gain access to the CF card.
The CF card is classified into two types, a memory card and an I/O card. When the information processing device exchanges data with the CF card of the memory card type which is inserted into the card slot, one of two operation modes, a memory mode or a True IDE mode, is used.
The information processing device is able to exchange data with the CF card in either the memory mode or the True IDE mode. However, because a method of gaining access to the CF card in the True IDE mode realizes a high communication rate, the information processing device checks the operation mode of the inserted CF card. In addition, the information processing device gains access to the CF card operable in the True IDE mode in a PIO mode of the True IDE mode or gains access to the CF card not operable in the True IDE mode in the memory mode (for example, see JP-A-2004-355476).
However, in some CF cards, a communication rate corresponding to the memory mode is faster than a communication rate corresponding to the PIO mode of the True IDE mode. In this case, the time necessary for data transmission can be reduced, when the memory mode is used. Therefore, in JP-A-2007-183879, the communication rate corresponding to the memory mode and the communication rate corresponding to the PIO mode of the True IDE mode are checked to select the operation mode in which a faster communication rate is realizable and gain access to the CF card.
However, it was known that even when the information processing device gains access to the CF card at a communication rate in which normal data exchange is possible, a communication error occurs and thus data are not able to be normally exchanged in some cases. It was known that the communication error occurs, because there are various kinds of CF cards manufactured by various makers, a communication rate which is designed to be compatible in accordance with the maker or the kinds of CF cards is not compatible, or there is a mismatch with a driver. In these cases, the CF card is not able to be used and thus this problem causes inconvenience to the user.
In order to solve this problem, JP-A-2007-241523 discloses an information processing device in which the communication rate is decreased to realize data exchange with the data record medium, when the data exchange even at the originally compatible highest communication rate fails and in which waiting time of a user is as short as possible by determining whether to switch the operation mode between the memory mode and the PIO mode of the True IDE mode depending on a type of access to the data recode medium.
However, recent CF cards are used in an Ultra DMA mode as well as the PIO mode in the True IDE mode. Therefore, in this case, it is necessary to select the operation mode among three modes, that is, the memory mode, the PIO mode, and the Ultra DMA mode.
Moreover, when the operation mode is switched between the memory mode as a first operation mode and the True IDE mode as a second operation mode, power supply to the CF card has to be stopped for some time. However, when the operation mode is switched between sub-operation modes of the True IDE mode, that is, the PIO mode as a first sub-operation mode and the Ultra DMA mode as a second sub-operation mode, the power supply to the CF card does not need to be stopped.
Accordingly, even when the access to the data record medium fails, it is necessary to again select an appropriate operation mode to be used to gain access to the data record medium depending on the type of access to the data record medium and a present operation mode, that is, the memory mode as the first operation mode, the PIO mode as the first sub-operation mode, or the Ultra DMA mode as the second sub-operation mode. The invention is not limited to the CF card, but may be applied to other data record media in the same manner.